Electrolytic synthesis of organic compounds in an electrolytic cell has generally proven to be industrially unsatisfactory. This is because of the necessity of providing a current carrier, i.e., an ionizable molecule, to carry charge between the anode and the cathode. The organic reactants and products themselves generally will not perform this function because of their lack of ionic character.
One attempt at eliminating the requirement for a dissolved, ionized, or liquid current carrying supporting electrolyte is disclosed in U.S. Pat. No. 3,427,234 to Guthke et al. and Japanese Pat. No. 56/23290 to Yoshizawa et al., both of which describe the use of a solid polymer electrolyte electrolytic cell to carry out the electrolytic synthesis of organic compounds. In a solid polymer electrolyte electrolytic cell the anode is in contact with one surface of the solid polymer electrolyte and the cathode is in contact with the other surface of the solid polymer electrolyte. The solid polymer electrolyte itself is a polymeric material having pendant ionic groups which enhance the ionic conductivity of the underlying polymer matrix. Thus, negatively charged particles may flow from the cathode through the solid polymer electrolyte to the anode without ever contacting the organic media. Likewise, positively charged particles may travel from the anode through the solid polymer electrolyte to the cathode without ever contacting the organic media. In the electrolytic synthesis described in Guthke et al. and Yoshizawa et al., the cathodic and anodic reactions take place at an electrode-liquid organic reactant interface, a surface of the cathode and a surface of the anode each being in contact with the solid polymer electrolyte. Charged particles traverse the solid polymer electrolyte as described hereinabove.
However, providing a solid polymer electrolyte in contact with both the anode and the cathode does not, alone, result in an industrially useful electrolytic cell for electroorganic synthesis. For example, the typical prior art permionic membrane materials described in U.S. Pat. Nos. 3,041,317 to Gibbs, 3,718,617 to Grot, and 3,849,243 to Grot, 4,065,366 to Oda et al., 4,116,888 to Ukihashi et al. and 4,126,588 to Ukihashi et al., and 4,151,053 to Seko et al., require water of hydration. The combination of water of hydration and immobilized ionic sites bonded to the polymer provide ionic conductivity through the permionic membrane. In the absence of water of hydration, the electrical resistivity of the permionic membrane and, more particularly, the resistance to ionic transport of the permionic membrane, is objectionably high.
As organic media are typically non-aqueous, the aforementioned permionic membranes employed in such organic media are unable to attain or maintain an equilibrium content of water of hydration. Similarly, where the reaction medium is an anhydrous gas phase medium (the reactants and products also being anhydrous gases), the aforementioned permionic membrane materials are incapable of maintaining an equilibrium water of hydration content.